Computer memory types Volatile * DRAM, e.g. DDR SDRAM * SRAM * Upcoming o Z-RAM o TTRAM * Historical o Williams tube o Delay line memory Non-Volatile * ROM o PROM o EAROM o EPROM o EEPROM o Flash memory * Upcoming o FeRAM o MRAM o PRAM o SONOS o RRAM o NRAM * Historical o Drum memory o Magnetic core memory o Bubble memory [edit] History (Add: Jacquard Loom as a non-electronic precursor) [edit] Use of ROM for program storage